1. Technical Field
The present invention relates to optical elements.
2. Related Art
An optical element may have a structure that includes a substrate, a columnar section that is formed above the substrate for light emission or light incidence, a resin layer formed around the columnar section, and an electrode electrically connected to an upper surface of the columnar section. For example, Japanese Laid-open Patent Application JP-A-2004-31633 describes a structure in which an additional protective film is provided between a substrate and a polyimide protective film to thereby prevent the polyimide protective film from peeling off.
It is noted that resin is relatively soft, and would likely expand or contract according to changes in temperature. Therefore it is important to prevent its deformation. Also, because resin (for example, a high polymer material such as polyimide resin) has a few permeability to moisture, there is a possibility that exfoliation of layers may occur due to absorption of moisture at an interface between the resin layer and an electrode or between the resin layer and a substrate.